1. Field of the Invention
This invention relates to an apparatus for supplying ink in a rotary press, and more particularly, to an apparatus for supplying ink wherein a fountain roller is rotatably disposed in an ink fountain having a width smaller than the maximum printing width of a rotary press.
2. Description of the Prior Art
Devices for supplying ink in the prior art wherein a fountain roller is disposed rotatably in an ink fountain having a width smaller than the maximum printing width of a rotary press are disclosed in U.S. Pat. No. 3,500,745 (hereinafter referred to as "prior art technique No. 1"), Japanese Utility Model Publication No. 31843/1970 (hereinafter referred to as "prior art technique No. 2"), U.S. Pat. No. 4,373,442 (hereinafter referred to as "prior art technique No. 3"), and so forth.
These prior art techniques are directed to the supply of several kinds of ink having different colors to various portions along the maximum printing width in a rotary press; to the partial supply of such ink; or to make ink exchange possible for each different portion along the maximum printing width.
In all of these prior art techniques, a fountain roller is disposed in an ink fountain removably fitted to the press. When the ink fountain is fitted to the press, the fountain roller can approach, or come into contact with, adjacent rollers. When the ink fountain is fitted to the press, the fountain roller rotates while part of it is dipped in ink inside the ink fountain so that its peripheral surface guides out ink and transfers and supplies it to the adjacent rollers.
In prior art technique No. 1, a gear is disposed on a driving shaft connected to a driving source and when the ink fountain is fitted to the press, the gear described above meshes with another gear disposed at the shaft end of the fountain roller and the fountain roller is thus driven for rotation.
In other words, the fountain roller can be rotated even though it does not come into contact with the adjacent roller and the ink supply can be made by changing the peripheral speed of rotation of the fountain roller and the adjacent rollers. Accordingly, in a rotary press that operates at a high speed, the peripheral speed of the fountain can be set to a speed at which ink can sufficiently attach to its peripheral surface, and to a speed at which ink inside the ink fountain is not stirred markedly. Therefore, scatter of ink and admixture of bubbles into ink can be restricted.
In prior art technique No. 2, the fountain roller can come into contact with the adjacent roller when the ink fountain is fitted to the press and is rotated together with the rotation of the adjacent roller which is interconnected to the driving source and driven for rotation.
In prior art technique No. 3, the fountain roller and a downstream roller coming into contact with the fountain roller are disposed in the ink fountain, the downstream roller comes into contact with its adjacent roller when the ink fountain is fitted to the press, and the downstream roller is rotated together with the adjacent roller which is interconnected to the driving source and driven for rotation. Furthermore, the fountain roller is rotated through this downstream roller.
Prior art techniques Nos. 2 and 3 described above have a structure such that when the fountain roller disposed in the ink fountain, or the downstream roller coming into contact with the fountain roller comes into contract with the adjacent roller which is driven for rotation, the fountain roller is rotated with the rotation of the adjacent roller. Since any driving shaft for driving the fountain roller is thus unnecessary, maintenance and inspection around the driving shaft is not necessary and the danger that might occur if this driving shaft and gears disposed on the driving shaft exist does not occur.
The prior art technique No. 1 needs maintenance and inspection around the driving shaft which drives the fountain roller. Since the driving shaft and the gear disposed on the driving shaft rotate with the operation of the press even when the ink fountain is not fitted, they can present hazards to the operator. Furthermore, the fitting position of the ink fountain and its size are limited by the position of the gear disposed on the driving shaft. Since the gear ratio is constant between the gear disposed on the driving shaft and the gear disposed at the shaft end of the fountain roller, the peripheral speed of the fountain roller cannot be changed, even though such a change is desired, without changing the peripheral speed of the adjacent roller, such as when it is desired to change the take-out quantity of ink or when ink having an extremely high or low viscosity is used.
In prior art techniques Nos. 2 and 3, the fountain roller is rotated with the rotation of the adjacent roller. Therefore, there is the possibility of the rotary press operating at such a high speed that the peripheral speed of the fountain roller is so high that ink cannot sufficiently attach to the peripheral surface of the fountain roller, or ink inside the ink fountain is stirred so much that scatter of ink and admixture of bubbles into ink are invited. Furthermore, slippage is likely to occur between the rollers that are in mutual contact with one another and non-uniform rotation of the fountain roller is likely to occur to some extent. Even when it is desired to change the peripheral speed of the fountain roller, it is not possible without changing the peripheral speed of the adjacent roller in the same way as the prior art technique No. 1.